In the art of drilling oil and gas wells, it is well known to count certain reoccuring events, such as the revolutions of the drill pipe, the number of strokes of a mud pump or the like. For example, during oil and gas drilling and production operations it is necessary to monitor various events to provide adequate control and safety. The pump stroke of the drilling mud slush pump is continuously monitored during an oil and gas well drilling operation to monitor the mud being pumped into the well. In the prior art, mechanical contact switching systems have been used to count the pump strokes. These mechanical connections have disadvantages and in order to advance the state of the art of oil and gas drilling and production, it is desirable to improve the systems for transmitting pump stroke information. The prior art systems have encountered the problems of poor access to the reciprocating or rotary element due to its motion and location, and vulnerability of pick-ups due to routine machine maintenance and wear of contacting parts. The present invention will result in fewer service problems due to failure or misalignment and will provide consistent accuracy.